1. Field of the Invention
This invention relates to pharmaceutical compositions. More particularly, this invention relates to topical ophthalmic compositions comprising 5-benzoyl-2,3-dihydro-1H-pyrrolizine-1-carboxylic acid, otherwise known as ketorolac.
2. Description of the Related Art
Topical nonsteroidal anti-inflammatory drugs (NSAIDs) are used to control pain and postoperative inflammation. All drugs are associated with some adverse effects. With the use of NSAIDS in topical ophthalmic treatment of patients, surface toxicity has been a concern, and incidents of keratitis, corneal subepithelial infiltrates, ulceration, and corneal melts have been reported (Guidera et al, Ophthalmology, 2001, 108 (5), pp. 936-944; Solomon et al, J Cataract Refract Surg, 2001, 27 (8), pp. 1232-1237; Teal et al, J Cataract Refract Surg, 1995, 21(5), pp. 516-518). Further, patients often report burning or stinging on instillation (Jaanus et al, Antiinflammatory Drugs. Clinical Ocular Pharmacology, Bartlet, J. D. and Jaanus, S. D., Ed., Boston: Heineman, 2001, pp. 265-298). The burning or stinging could be related to the concentration of the active component of the formulation.
Ketorolac tromethamine 0.5% (w/v) ophthalmic solution, available from Allergan, Inc., under the tradename Acular®, is a safe and effective NSAID with proven analgesic and anti-inflammatory activity. The most common adverse event associated with the use of the 0.5% ketorolac formulation is ocular irritation, primarily burning, and stinging on instillation. Eliminating or reducing ocular irritation has the potential for improving tolerability, compliance, and effectiveness of treatment.